SPI, 09-6110971026209152C, 2 SPI Pistons, Bearings & Gasket Kit Arctic Cat ZR800, ZL800, Mountain Cat 800 & Pantera 800 Manufactured by SPI Includes 2 piston kits, bearings & top end gasket kit (everything pictured) Pistons are for standard bore size 81.00mm SPI pistons are engineered to provide the best possible path for combustion chamber heat transfer to the cylinder walls